"I have patients who've been locked up for 40 years," Levin says. "They have no idea how to get refills, how to go to a pharmacy. Often, they don't know how to take their own medications, especially things like insulin."

When prisoners get out, they often don't have jobs and, therefore, don't have health coverage. The insurance piece could be changing soon, though.

The eligibility requirements for Medicaid are expanding in 2014 as a part of the health overhaul law. Right now, Medicaid in most states is mainly targeted toward children, families and the disabled. After the Medicaid expansion goes into effect, single adults who meet income requirements will be eligible, even if they don't have kids.

Some states and the District of Columbia have gotten a head start and rolled out the Medicaid expansion early. That means Levin can get reimbursed for the care she provides to patients like Keith Snowden, a D.C. resident who got out of prison last year.

Snowden had been dealing with uncontrolled high blood pressure for years, even before he went to prison in 2009 for selling stolen cars and counterfeit IDs. At his first post-prison visit to Levin's clinic, his blood pressure was off the charts.

"The hospital was right next door. They wouldn't let me walk next door," Snowden recalls. "I had to have the ambulance come pick me up. It was that bad."

Snowden says he had been taking blood pressure drugs for years to no effect. Levin conducted a barrage of tests and eventually discovered the culprit: a tumor weighing on his adrenal gland. Snowden had it surgically removed recently; now his blood pressure is back on the charts.

"It took the free doctor for me to go and figure out my problem," Snowden says. "I really owe my life to her for being so diligent and trying to figure this out."

Calling Levin a "free doctor" isn't entirely accurate. Her clinic is a federally qualified community health center run by the charitable non-profit Unity Health Care. Doctors and other caregivers there treat patients regardless of their ability to pay, but the kind of life-saving care Levin provided to Snowden costs money.

Levin says it's much easier to provide appropriate care now that Washington has moved forward with the health law's Medicaid expansion, allowing her patients to get health insurance.

"Now, everyone gets Medicaid," she says. "And suddenly I can get them their medications, I can get them to see a specialist, I can get the studies done. And it is amazing. It's completely changed my practice."

Not everyone getting out of prison will be eligible for Medicaid, however. The governors of at least half a dozen states say they won't participate in the Medicaid expansion because it's too expensive.

When prisoners leave prison they often don't have jobs and, therefore, no health insurance. That means they have a difficult time getting even basic health care. But under the federal health law, that could change. As Medicaid expands, the program will begin to be offered to all adults, not just those with children. And that includes newly released prisoners. In Washington, D.C., a local clinic has a program specifically designed for ex-prisoners and is seeing benefits from the Medicaid expansion.

David Schultz, with our partner Kaiser Health News, has more on how it works.

DAVID SCHULTZ, BYLINE: The first time Keith Snowden had his blood pressure measured after he got out of prison, his doctors thought their machines were broken. Snowden's pressure was at 227 over 153 - off the charts.

DAVID SNOWDEN: The hospital was right next door. They wouldn't let me walk next door. I had to have the ambulance come pick me up. It was that bad.

SCHULTZ: Snowden had been dealing with out-of-control hypertension for years, even before he went to prison in 2009 for selling stolen cars and counterfeit IDs. When he got out, he didn't have a job, which meant he didn't have health insurance, which meant he didn't have a doctor. So Snowden went to a free clinic in southeast D.C. run by the nonprofit group, Unity Health Care. His doctor, Ilse Levin, says she sees patients like Snowden all the time.

ILSE LEVIN: I have patients who've been locked up for 40 years. They have no idea how to get refills, how to go to a pharmacy. Often, they don't know how to take their own medications, especially things like insulin.

SCHULTZ: After a barrage of tests, Levin realized that Snowden's hypertension was being caused by a tumor weighing on his adrenal gland. Snowden had it removed, now his blood pressure is back on the charts.

KEITH SNOWDEN: It took the free doctor for me to go to and figure out my problem. Really, I, you know, really owe my life, you know, to her for being so diligent and to, you know, trying to figure this out.

SCHULTZ: Calling Levin a free doctor isn't entirely accurate. The kind of life-saving care she provided to Snowden costs money. Levin says it's much easier to provide that care now that D.C. has moved forward with the federal health law and expanded it to all adults.

LEVIN: Now, everyone gets Medicaid and I can suddenly, I can get them their medications, I can get them to see a specialist, I can get the studies done. And it is amazing. It's completely changed my practice.

SCHULTZ: Unity Health Care began more than 25 years ago as a free clinic for the homeless in Washington. It's since expanded to 13 health centers throughout the District, including its newest one, a 28,000 square foot facility built with federal stimulus funds. This new clinic gives Unity the space to offer more services. Its ex-prisoner program, for example, has just as many social workers as it does doctors.

VINCENT KEANE: You have to focus on the whole person. You're dealing with a, you know, very vulnerable population. You know, many of the people who are discharged are discharged to homeless shelters. They don't have a place to go.

SCHULTZ: Vincent Keane is the president of Unity Health Care. He started working there 22 years ago after a stint as a Catholic priest. Keane is used to having to explain to people why ex-convicts deserve to have health care. There's the financial argument...

KEANE: If you can get people into primary preventative care, we are ultimately going to save money.

SCHULTZ: There's the public health argument...

KEANE: Public health and diseases cannot be enshrined in prison bars.

SCHULTZ: But the argument Keane voices most passionately is the argument for compassion.

KEANE: We live right now in what I call a very judgmental society. I think from the values of the United States and everything we believe in should lead us to understand that the principles that we stand on calls for compassionate, effective health care.

SCHULTZ: Not everyone is swayed by this reasoning. The governors of at least half a dozen states say they won't participate in the Medicaid expansion because it's too expensive. But 700,000 people will be getting out of prisons across the U.S. every year, according to one study. Doctors and policy makers will have to figure out some way to treat this newly-released, newly-insured population. For NPR News, I'm David Schultz. Transcript provided by NPR, Copyright NPR.